Philadelphia Water Department

The Philadelphia Water Department says water service is normal for everyone in Old City and Society Hill after Saturday’s massive water main break at 3rd and Walnut, but the gigantic hole created remains.

It’s lurking in the nation’s sewers, and even as close as the sewage line that runs from your house to the main. It’s called FOG — for accumulated fats, oils and grease. In Philly, it’s FROG, since the water department includes tree roots.